Language Selection

English French German Italian Portuguese Spanish

Linux: Tuning CFS

Filed under

Nick Piggin used 'git bisect' to track a lmbench regression to the main CFS commit, leading to an interesting discussion between Nick and Ingo Molnar. Ultimately the regression was tracked down to the temporary configurability of the scheduler while it is tuned for optimal performance, "one reason for the extra overhead is the current tunability of CFS, but that is not fundamental, it's caused by the many knobs that CFS has at the moment." The solution, already coded but not yet merged in the mainline kernel "changes those knobs to constants, allowing the compiler to optimize the math better and reduce code size," and as a result result, "CFS can be faster at micro-context-switching than 2.6.22."

Ingo described the lmbench configuration in question as a "micro-benchmark", and noted that with a macro-benchmark better performance was more pronounced, "because with CFS the _quality_ of scheduling decisions has increased.

More Here

More in Tux Machines

Type Title Author Replies Last Postsort icon
Story KDevelop 5.1.1 released Rianne Schestowitz 27/05/2017 - 11:19pm
Story Linux Devices: FriendlyElec, NComputing, CubieTech Rianne Schestowitz 27/05/2017 - 11:13pm
Story Security Leftovers Rianne Schestowitz 27/05/2017 - 10:51pm
Story Android Leftovers Rianne Schestowitz 27/05/2017 - 10:47pm
Story The Past Week in Techrights (Still on Holiday) Rianne Schestowitz 27/05/2017 - 8:07pm
Story First LXQt-Based Lubuntu 17.10 Daily Builds Surface, Here's What It Looks Like Rianne Schestowitz 27/05/2017 - 7:05am
Story Mageia 6 RC Rianne Schestowitz 27/05/2017 - 6:33am
Story Fedora and Red Hat Rianne Schestowitz 27/05/2017 - 6:16am
Story Debian and Devuan News Rianne Schestowitz 27/05/2017 - 6:04am
Story Gaming News Rianne Schestowitz 27/05/2017 - 5:54am